In U.S. Pat. No. 3,309,016, O'Brien states a computation of centrifugal force required to remove salts from water. This amount of centrifugal force was reduced by Kirk's in U.S. Pat. No. 3,430,853 by removing swirl from within the high gravity chamber. In U.S. Pat. No. 3,880,347 the Kirk's added inertia as a separation force.